This makes identical siblings perfect comparison points for researchers looking to
determine which traits are genetic and which are the result of environmental factors.

So an area on the festival grounds was lined with tents where researchers welcomed
twins to participate in genetic studies that focus on subjects including aesthetics, biometrics,
social skills and taste perception.

Researchers say they love the festival because under normal circumstances,
collecting data from large numbers of twins can be difficult.

“This year we tested exactly 360 people,” said Danielle Reed, a researcher from the
Monell Chemical Senses Center in Philadelphia.

“It compresses a year’s worth of work into two days.”

...

Identical twins are ideal subjects for cosmetic researchers because they should age
exactly the same, said Dr. Bahman Guyuron, chairman of plastic and reconstructive surgery at
University Hospitals’ Case Medical Center in Cleveland.

Any differences can be attributed to environmental factors.

Researchers from University Hospitals and Procter & Gamble traveled to
Twinsburg this month.

“We have a bunch of researchers who go there every Twins Days,” Guyuron
said. “It is an enormous, enormous source of information.”

One notable finding by University Hospitals researchers is that people older than
40 appear older when they weigh less. The opposite is true for younger people.

“Part of aging is loss of volume from the face. … It shows the wrinkles,” Guyuron
said. “When the individual gains some weight, there’s more volume in the face, and the skin is
thicker.”

That’s why products that fill in these wrinkles make older adults appear
younger.

Researchers with Olay, a Procter & Gamble company, made the same observation,
said Mary Johnson, an Olay principal scientist.

The two groups say external factors including divorce, smoking, heavy drinking and
unprotected sun exposure also play a substantial role in visual aging.

Breast shape, hair loss and facial symmetry are other genetic traits that
University Hospitals researchers are studying in twins.

This year, researchers took on migraine headaches to see if twins suffer the same
patterns and trigger sites.

“Through these studies, we can find out if the conditions are environmental or
avoidable,” Guyuron said. “Our goal is to help the public to modify what they do to minimize the
ill effects that can come about from some environmental fac-Dawson said West Virginia
researchers want to learn more about fingerprints among twins, which are more similar than those
among non-twin siblings.

The research, he said, asks “what level is that correlation, exactly?”

Twins stopped by the university’s tents and had images taken of their faces, irises
and fingerprints.

Dawson said the university’s biometric research could help law enforcement with
improved software recognition programs.

Youngstown State University researchers are looking at fingerprints as well.

“We already know identical twins don’t have matching fingerprints, but we want to
see if software can differentiate,” said Ashley Kilmer, a graduate student studying criminal
justice at Youngstown State.

“Since so many more law-enforcement agencies rely on fingerprint software, we need
to find out if they work.”

...

Hillary Elfenbein, a researcher with Washington University’s Olin
Business School in St. Louis, is interested in whether interpersonal skills, such as negotiating,
are inherited or learned.

She suspects both.

“We sometimes have intuition that we’re just born that way,” Elfenbein said. “Where
do those skills come from?”

For her work, she split up twins and had them go through negotiation exercises with
other twins.

Elfenbein said identical twins’ scores can then be compared to fraternal twins’
scores.